Re: [PATCH] extcon: extcon-dra7xx: Add Extcon driver for DRA7xx

[George Cherian <george.cherian-l0cyMroinI0@public.gmane.org>]

On 6/16/2014 10:29 AM, Guenter Roeck wrote:
> On 06/15/2014 07:42 PM, George Cherian wrote:
>> This is the driver for the USB ID pin detection. This driver
>> handles only the USB ID pin changes generated by cable
>> insertion/removal.
>>
>> Signed-off-by: George Cherian <george.cherian-l0cyMroinI0@public.gmane.org>
>
> Hi George,
>
> Curious: Why can't you use extcon-gpio ?
Main reason being missing dt support.
>
> Also, I thought that Linux specific bindings would be unacceptable.
> "ti,dra7xx-extcon" looks very linux specific to me. Did the rules 
> change ?
>
Then how about "ti,extcon-usbid" ?
> Thanks,
> Guenter
>
>> ---
>>   .../devicetree/bindings/extcon/extcon-dra7xx.txt   |  15 ++
>>   drivers/extcon/Kconfig                             |   5 +
>>   drivers/extcon/Makefile                            |   1 +
>>   drivers/extcon/extcon-dra7xx.c                     | 164 
>> +++++++++++++++++++++
>>   4 files changed, 185 insertions(+)
>>   create mode 100644 
>> Documentation/devicetree/bindings/extcon/extcon-dra7xx.txt
>>   create mode 100644 drivers/extcon/extcon-dra7xx.c
>>
>> diff --git 
>> a/Documentation/devicetree/bindings/extcon/extcon-dra7xx.txt 
>> b/Documentation/devicetree/bindings/extcon/extcon-dra7xx.txt
>> new file mode 100644
>> index 0000000..69c3804
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/extcon/extcon-dra7xx.txt
>> @@ -0,0 +1,15 @@
>> +EXTCON FOR DRA7xx USB
>> +
>> +Required Properties:
>> + - compatible : Should be "ti,dra7xx-extcon"
>> + - gpios : specifies the gpio pin used for ID pin detection.
>> +
>> +
>> +Please refer to ../gpio/gpio.txt for details of the common GPIO 
>> bindings
>> +
>> +Example:
>> +
>> + dra7xx_extcon {
>> +                compatible = "ti,dra7xx-extcon";
>> +                gpios = <&gpio21 1 0>;
>> +        };
>> diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
>> index aebde48..1481b7f 100644
>> --- a/drivers/extcon/Kconfig
>> +++ b/drivers/extcon/Kconfig
>> @@ -70,4 +70,9 @@ config EXTCON_PALMAS
>>         Say Y here to enable support for USB peripheral and USB host
>>         detection by palmas usb.
>>
>> +config EXTCON_DRA7XX
>> +    tristate "DRA7xx USB ID detection EXTCON support"
>> +    help
>> +      Say Y here to enable support for USB ID detection for DRA7xx.
>> +
>>   endif # MULTISTATE_SWITCH
>> diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
>> index bf7861e..b5f7cac 100644
>> --- a/drivers/extcon/Makefile
>> +++ b/drivers/extcon/Makefile
>> @@ -10,3 +10,4 @@ obj-$(CONFIG_EXTCON_MAX77693)    += extcon-max77693.o
>>   obj-$(CONFIG_EXTCON_MAX8997)    += extcon-max8997.o
>>   obj-$(CONFIG_EXTCON_ARIZONA)    += extcon-arizona.o
>>   obj-$(CONFIG_EXTCON_PALMAS)    += extcon-palmas.o
>> +obj-$(CONFIG_EXTCON_DRA7XX)    += extcon-dra7xx.o
>> diff --git a/drivers/extcon/extcon-dra7xx.c 
>> b/drivers/extcon/extcon-dra7xx.c
>> new file mode 100644
>> index 0000000..2f80509
>> --- /dev/null
>> +++ b/drivers/extcon/extcon-dra7xx.c
>> @@ -0,0 +1,164 @@
>> +/*
>> + * DRA7xx-Extcon  USB ID pin detection driver
>> + *
>> + * Copyright (C) 2014 Texas Instruments Incorporated - 
>> http://www.ti.com
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
>> + *
>> + * Author: George Cherian <george.cherian-l0cyMroinI0@public.gmane.org>
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/err.h>
>> +#include <linux/extcon.h>
>> +#include <linux/gpio.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_gpio.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/platform_device.h>
>> +
>> +struct dra7xx_extcon {
>> +    struct device *dev;
>> +    struct extcon_dev edev;
>> +
>> +    int id_gpio;
>> +    int id_irq;
>> +};
>> +
>> +static const char *dra7xx_extcon_cable[] = {
>> +    [1] = "USB-HOST",
>> +    NULL,
>> +};
>> +
>> +#define ID_GND        0
>> +
>> +static irqreturn_t id_irq_handler(int irq, void *data)
>> +{
>> +    struct dra7xx_extcon *dra7xx_extcon = (struct dra7xx_extcon *)data;
>> +    int id_current;
>> +
>> +    id_current = gpio_get_value_cansleep(dra7xx_extcon->id_gpio);
>> +    if (id_current == ID_GND)
>> +        extcon_set_cable_state(&dra7xx_extcon->edev, "USB-HOST", true);
>> +    else
>> +        extcon_set_cable_state(&dra7xx_extcon->edev, "USB-HOST", 
>> false);
>> +
>> +    return IRQ_HANDLED;
>> +}
>> +
>> +static void dra7xx_extcon_set_initial_state(struct dra7xx_extcon 
>> *dra7xx_extcon)
>> +{
>> +    int id_current;
>> +
>> +    id_current = gpio_get_value_cansleep(dra7xx_extcon->id_gpio);
>> +    if (id_current == ID_GND)
>> +        extcon_set_cable_state(&dra7xx_extcon->edev,
>> +                       "USB-HOST", true);
>> +    else
>> +        extcon_set_cable_state(&dra7xx_extcon->edev,
>> +                       "USB-HOST", false);
>> +}
>> +
>> +static int dra7xx_extcon_request_irq(struct dra7xx_extcon 
>> *dra7xx_extcon)
>> +{
>> +    int ret;
>> +
>> +    ret = devm_request_threaded_irq(dra7xx_extcon->dev,
>> +                    dra7xx_extcon->id_irq,
>> +                    NULL, id_irq_handler,
>> +                    IRQF_ONESHOT | IRQF_TRIGGER_FALLING,
>> +                    dev_name(dra7xx_extcon->dev),
>> +                    (void *)dra7xx_extcon);
>> +    if (ret) {
>> +        dev_err(dra7xx_extcon->dev, "failed to request id irq #%d\n",
>> +            dra7xx_extcon->id_irq);
>> +        return ret;
>> +    }
>> +    return ret;
>> +}
>> +
>> +static int dra7xx_extcon_probe(struct platform_device *pdev)
>> +{
>> +    struct device_node *node = pdev->dev.of_node;
>> +    struct dra7xx_extcon *dra7xx_extcon;
>> +    int ret, gpio;
>> +
>> +    dra7xx_extcon = devm_kzalloc(&pdev->dev, sizeof(*dra7xx_extcon),
>> +                     GFP_KERNEL);
>> +    if (!dra7xx_extcon)
>> +        return -ENOMEM;
>> +
>> +    dra7xx_extcon->dev = &pdev->dev;
>> +
>> +    platform_set_drvdata(pdev, dra7xx_extcon);
>> +
>> +    dra7xx_extcon->edev.supported_cable = dra7xx_extcon_cable;
>> +
>> +    gpio = of_get_gpio(node, 0);
>> +    if (gpio_is_valid(gpio)) {
>> +        dra7xx_extcon->id_gpio = gpio;
>> +        ret = devm_gpio_request(&pdev->dev, dra7xx_extcon->id_gpio,
>> +                    "id_gpio");
>> +        if (ret)
>> +            return ret;
>> +
>> +        dra7xx_extcon->id_irq = gpio_to_irq(dra7xx_extcon->id_gpio);
>> +    } else {
>> +        dev_err(&pdev->dev, "failed to get id gpio\n");
>> +        return -EPROBE_DEFER;
>> +    }
>> +
>> +    ret = dra7xx_extcon_request_irq(dra7xx_extcon);
>> +    if (ret)
>> +        return ret;
>> +
>> +    ret = extcon_dev_register(&dra7xx_extcon->edev);
>> +    if (ret) {
>> +        dev_err(&pdev->dev, "failed to register extcon device\n");
>> +        return ret;
>> +    }
>> +
>> +    dra7xx_extcon_set_initial_state(dra7xx_extcon);
>> +
>> +    return 0;
>> +}
>> +
>> +static int dra7xx_extcon_remove(struct platform_device *pdev)
>> +{
>> +    struct dra7xx_extcon *dra7xx_extcon = platform_get_drvdata(pdev);
>> +
>> +    extcon_dev_unregister(&dra7xx_extcon->edev);
>> +    return 0;
>> +}
>> +
>> +static struct of_device_id of_dra7xx_extcon_match_tbl[] = {
>> +    { .compatible = "ti,dra7xx-extcon", },
>> +    { /* end */ }
>> +};
>> +
>> +static struct platform_driver dra7xx_extcon_driver = {
>> +    .probe = dra7xx_extcon_probe,
>> +    .remove = dra7xx_extcon_remove,
>> +    .driver = {
>> +        .name = "dra7xx-extcon",
>> +        .of_match_table = of_dra7xx_extcon_match_tbl,
>> +        .owner = THIS_MODULE,
>> +    },
>> +};
>> +
>> +module_platform_driver(dra7xx_extcon_driver);
>> +
>> +MODULE_ALIAS("platform:extcon-dra7xx");
>> +MODULE_AUTHOR("George Cherian <george.cherian-l0cyMroinI0@public.gmane.org>");
>> +MODULE_DESCRIPTION("USB ID pin detection driver for DRA7xx");
>> +MODULE_LICENSE("GPL");
>> +MODULE_DEVICE_TABLE(of, of_dra7xx_extcon_match_tbl);
>>
>


-- 
-George

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